ScanWorks® High-Speed I/O Validation Solutions

Problem:

Validating the signal integrity of a high-speed I/O bus with legacy probe-based testers or external instruments has become far less effective and more costly. Why?

• Access for probes is vanishing because test pads corrupt the bus’ signaling.
• Probing a high-speed bus often breaks it. Placing a probe on a HSIO is not allowed.
• Tolerances on high-speed buses decrease as speed increases.

Eye diagram shows that margins are on high-speed I/O buses are shrinking.

Solution: Seeing what the silicon sees

Validating high-speed I/O or memory buses can be a touchy subject. If you’ve tried it, you know how sensitive they can be. And it will only get worse. As bus speeds inevitably accelerate, validating signal integrity becomes that much more difficult.

The ScanWorks® high-speed I/O validation solution doesn’t rely on touching the bus with a probe the way intrusive legacy technologies like oscilloscopes and logic analyzers do. At speeds of around five giga-transfers per second (GT/s) I/O buses become super-sensitive to coupling effects. Test pads placed on a bus to facilitate probing will introduce capacitive anomalies into the signaling, making suspect any validation data gathered by an intrusive probe-based instrument. And filtering that data with higher-order math only results in a simulation of the signal, not the real signal. Plus the price tag on that higher-order math can be staggering.

The solution is to avoid touching the bus at all. That’s what the ScanWorks platform for embedded instruments does. Its high-speed I/O validation solution draws on the multiple validation, test and debug toolkits which comprise the ScanWorks platform. And since the software-based ScanWorks depends on instrumentation that’s already embedded in chips and on circuit boards, it validates a bus’ signal integrity non-intrusively from inside the board instead of externally by way of a physical probe.

The ScanWorks high-speed I/O solution is a measurement tool that validates the performance of fast serial and parallel buses by capitalizing on embedded instruments such as bit error rate test (BERT) engines, margining and pattern generators. ScanWorks empirically validates the signal integrity and measures actual performance at the receivers on a bus. In a very real sense, ScanWorks sees what the silicon sees.

Since it is a platform for validation, test and debug, ScanWorks is not limited to the capabilities of any one toolkit. For example, the ScanWorks high-speed I/O validation solution is able to measure certain parameters like voltage and timing and, by doing so, provide defect test coverage that is not available from other test tools. Moreover, the diagnostic granularity of the ScanWorks high-speed I/O validation tools are quite precise.

Resources:

Ircona Case Study
An ASSET customer explains how ScanWorks HSIO helped their team identify a fault on a high-speed bus and correct it before the board went into manufacturing.

Check out these other ScanWorks solutions:

• Non-intrusive Board Test (NBT)
• Embedded Diagnostics
• Board Bring-Up

Contact us for more information on the ScanWorks® High-Speed I/O Solutions.